Wait, a 3D Printed Lawn mower?

Well, we have to admit, we never saw this coming… A 3D printed lawn mower? What? Why? Huh? How? Those were at least a few of the thoughts running through our head when we saw this come in on the tips line.

[Hans Fouche] has a giant 3D printer that takes up most of the space in his garage, and after printing several large vases, a briefcase, bowls, and even a wind turbine blade — he decided to try printing a lawnmower. A freaking lawnmower.

To do so, he reverse engineered his old rusty lawn mower, and redesigned it to be printable. Apart from the steel axles, some fastening hardware, and of course the motor and blade, the entire thing is 3D printed. And it looks like it works pretty good too.

According to the article, [Fouche] has been 3D printing stuff for the past 18 years — using hot glue, icing sugar, and even chocolate. But when he bought a 3D printer with a standard 0.5mm nozzle, he got frustrated with how slow it was, so he decided to build his own.

He calls the gigantic 3D printer the Cheetah, and with good cause — it’s capable of spewing out 1kg of plastic per hour. This equates to a layer height of about 2.5-3mm, which is pretty impressive considering the hot-end actually processes plastic pellets, not filament. He’s even planning on manufacturing and selling it, after he tidies up the design a little bit.

Large format 3D printing certainly opens up some interesting possibilities for things you wouldn’t think could be 3D printed… After all, do you remember that life-size 3D printed concrete castle?

Yes but the housing of electric lawnmowers is metal AND THE MOTOR is also mounted to said metal housing so if it kicks up a rock the entire body of the lawnmower doesn’t desintegrate and fling the rock out, possibly destabilizing the entire spinning mess or dislodging the motor as well.

Interesting point…. The hard-hats that people wear on a construction site are made of ABS plastic, tha same as what this lawnmower is made off…. Can you please tell all of them that it is very dangerous, and that they mus wear steel hats please…..

@Fouche Have you thought of printing string blades (forgot what they are actually called but they are used for weed whackers and such) for the mower or would it not be strong enough for use in the mower?

The problem with String is the Z-axis movement of them. Hence why they’re okay in trimmers and weed whackers, because you’re typically not going for that much uniformity when plowing down weeds, or trimming the edges (since usually concrete provides the “clean” edge. I would think you’d run in to all kinds of problems with uniformity in height in a lawnmower because the strings would be affected not only by the grass still in the ground, but the clippings flying around in the housing and the buildup thereof.

Of course you’d also have to custom design a spool and it would be different based on the diameter of the housing and deal with string fragments being tossed around inside the housing against the active strings.

The up-side though, is that you could potentially use one of those DIY plastic string extruders to repurpose plastic bottles in to your spools (rather than printing new spools from the pellets).

I think that weed whackers/strimmers tend to use nylon (or glass fibre re-inforced nylon for the heavy duty jobs), but if the feed stock for your 3d printer is strong enough, then it would work straight off the spool. Might be cheaper just to buy the nylon though it probably comes in a site less per meter than 3D printer spools.

I was just thinking along the lines of whether the strength of the printed material would hold up to the punishment that would allow for him to print it out as well. This would eliminate the need to reuse the blade. Though, since he has printed a wind turbine, I guess it’s possible that he could have printed a proper blade for it.

My only concern would be the blade coming loose/shattering from an impact. That plastic will likely not stop the pieces from escaping the deck. converting to a string type system would be much better IMHO. Just print out a string holder, add nylon string and go. Converting to string would allow for conversion to battery power and more mobility as well….hmmm..I have an old cordless drill and some spare battery packs out in the garage…hmmm…..

As far as it being made out of plastic…why not? Most new push mowers have injection molded wheels already and many of the parts are plastic, including deflectors and shields.

Very true. Even so, this is probably much thicker in cross section than most IMPP or other injection molded parts. Not the best choice of materials, given the design, but with modification, could be quite safe.

Hi, good point! With this method, any thickness of solid ABS can be done. This can NOT be done with injection moulding….take note prease. With this method, thick, and thin parts can be done right next to each other. Only engineers will understand this , though….

sorry I don’t know if you post meant to come off as arrogant as I’m reading it or if it’s just the way to me but no… to almost every point you raised

you CAN easily injection mold varying thicknesses of material in one mold in fact it’s easier and quicker then 3d printing it, do you not understand how that woks? true there are areas that 3d printers have advantages over injection molding but that isn’t one of them. and it’s not something special only “engineers” would understand, honestly you might as well have call us all sub humanly stupid.

you’re on the wrong site for that BS sir.

we might not have all have engineering degrees but we know better than to use a structurally weak martial for a such an important part. ply wood would have been a much safer opinion to use for the main body so don’t go around being so arrogant when you get called on should an obvious flaw. now 3d printers, specially fused plastic prints, are nice tools but they are not the end all be all of tools and its get old when people act like they are.

Yes, the picture shows that on the next generation after that failure, you attempted to compensate by:

1) Making the outside of the wheel thicker.
2) Adding a spoke structure which acts as a shock absorber, rather than being rigid.

I also suspect the failure may have been due to printing the circumference of the wheel starting at the same point on each layer, leading to a weakness in that area that extends through the entire print thickness. If so, then hopefully you’re now changing that on each layer, to distribute the weak points.

All of these are valid workarounds for dealing with the lesser strength of fused plastic vs. molded/cast, but workarounds nonetheless. Sure, the 4th generation of wheels are working fine, but that also means that there were three previous generations that were at one point working fine and you had confidence in, until they unexpectedly failed. Next year maybe you’ll be on generation #5. And that’s ok. Break a wheel, no big deal; print another, better one, and move on.

But it’s perfectly reasonable for people to express distrust in the ability of an entirely 3D-printed lawnmower deck to safely contain thrown objects anywhere near as well as one made using traditional manufacturing techniques.

A steel plate can work, but it is extra work. The current ABS shield is 6mm. In CAD it can be made to 9mm in one minute, or 12mm, or 25mm ….. Some calculations, ore tests, must be made before further speculation…..

This mower remind me of one that my dad has built back in the day during the late part of the communism in my country. A 220V motor scavenged from some machine, a round plastic plate cut out of thick bakelite or what it was to mount it, wheels from an on child pram …

It certainly did work, but I would recommend anyone trying to build something involving quickly spinning blades to install a safety switch (dead man’s handle) and to wear thick work shoes. The first will prevent your foot from getting mangled/cut off if you trip and fall over the device/have the mower run over your leg and the latter will protect your legs from flying shrapnel that all mowers occasionally eject – rocks, shredded branches, sometimes pieces of the cutting blade (not all mowers use a nylon string!). Lessons learned the hard way …

Hans, but why are you wearing those flip-flops in that video? That is really asking for an accident :(

Unfortunately, many people do this – even mowers that use strings instead of fixed blades can (and do) eject bits and pieces and a piece of nylon string flying out and hitting your leg at high speed will certainly leave a mark.

On the other hand, your mower certainly looks designed in a saner way than what my dad has constructed, especially the electrical part – my dad has a rather peculiar understanding of all things electric and loves doing things “in his own way”. In short, that thing was pretty much a deathtrap for anyone else but him.

That’s awesome…until he mows a half-buried rock and the plastic deck explodes. Not to shoot down the whole idea, but that scenario should probably be tested before sale. I hit a rock once on a 2-blade gas riding mower that instantly stopped the whole works and bent the blade about 90deg.

Naw, the handle mount to the deck will fail as it did on Flymow the first plastic mower reviewed in Pop-Sci back in the 60-70’s.
Maybe put castors on the front and never lift the front with the handle.
Yes Flymow had no wheels! Still the fiberglass deck gave way at the handle.

After reading your replies to what seem like rather innocuous (and often constructive) criticism, my confidence in your company has plummeted. There’s no way I’d ever trust something produced by someone who so readily rejects outside criticism.

It sure would be a shame if your name was associated with such comments into perpetuity, especially when it comes time to begin selling your 3D printer…

Sure does met many of the definitions of a hack, but unfortunately it also reinforces negative connotations of hacker/hacking. Hack was a negative term long before computer hackers of any sort appeared. IMO if the builder/owner is willing to write up the details the printer is worthy of featuring , but not this print. An E for effort is the best I could give thing.

props! (get it, haha)
I love the spirit in doing something crazy like a lawnmower.
But please wear steel towed boots when testing it! I don’t think anyone wants to see that followup post.
It’s like a 3d printed bike fork. it’s great while it works but eventually your face eats the road.
Good Luck.

At the moment the stoneguard is 6mm thick ABS. After a lot ow mowing, no stone have left a visible mark on the inside of that guard yet…. I will keep on inspecting it, an as soon as I find a stone damage mark that looks severe, I will change to 9mm, or 12mm…..or 21mm for that matter. That is how development work is done on sush a new product. Shooting for the hip, with unfounded remarks, is the way of a dickhead.

The Einsteins, Mandelas, Gates, Bransons, etc. all followed the easy path……. or did they?
Everything invention around us is based upon trial & error, working toward perfection.
Who has a perfect definition for the word “perfection”?

Many people say 3d printing is only suitable for 1 off prototype
things, because it is so slow….I agree, but what if….. you can make it 8 times faster….?
But that can not be done?
Well, it have been done….!!!
Look at the videos over athttps://www.facebook.com/pages/Fouche-Chocolates/217306118448036
Is that the same Fouche?
;-)
O, yes, it is!
And that machine have been running for 19 years now………!!!!
3D Printed chocolates have been done for 19 yeas..!!!!
So printing 8 lawnmowers at the same time?
Not to laugh at any more!
Hans Fouche
;-)

Good stuff Hans.
No issues with the design. With hackers it is after all, forever in progress. Serious lawnmower accidents can make a spectacular mess of feet though. The most common cause appears to be reversing with the mower, tripping over something, the reflex is to hold on to whatever is at hand. Pulling the lawnmower onto your feet and legs.
Everything is cool, but please, don’t reverse with a lawnmower.

For all the times people cry “not a hack” around here, this is very much a hack, and a great demonstration of a homebrew ginormous 3d printer. I’m impressed, and thankfully his pellet-fed beast of a printer will make iterating pretty easy.

In the mean time- common sense, aim away from face, and leather shoes. Nicely done.

Same design problem as the Neuton electric mower. The front wheels are set aout ahead of the arc of the blade so it’s not possible to cut right up against things like is possible with plain old metal deck mowers. The Neuton also has the same problem at the sides, the wheels are too far out so it’s no good for mowing up against walls and fences.